For screen shots of all major features see the extension homepage.
http://gmailskins.mozdev.org

Gmailskins adds the following features:

* Change the colour/skin of your inbox.
* Integrate your google homepage alongside your inbox. This allows you to view weather reports, rss feeds, news headlines, flickr recently added, google calendar module etc from your inbox.
* Easily insert images from your Picasa web album in to your emai...